Technician A says that broken vacuum hoses can cause an engine to run lean. Technician B says that vacuum leaks can cause poor fuel economy. Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Broken vacuum hoses can cause unmetered air to enter the engine, leading to a lean fuel mixture, which can cause the engine to run poorly or even stall. Additionally, vacuum leaks can throw off the engine's air/fuel ratio, leading to poor fuel economy.

Technician a Says That Broken Vacuum Hoses Can Cause an Engine